Applicant claims priority from French application 99/16725 filed December, 1999.
One type of miniature switch (e.g. 1 to 3 mm high) includes an actuator that can be pushed forward to depress a conductive member against a contact and thereby close the switch. One example of such miniature switch is shown in an earlier patent by one of the present inventors, U.S. Pat. No. 5,660,272, which shows a resilient sheet metal force-transmitting member that converts forward movement of the actuator into downward depression of a snap dome tripping member. Such sheet metal transfer member includes a plate that facilitates mounting of the transfer member on a miniature housing. However, such transfer member requires intricate bending of a tiny piece of sheet metal. A simpler and more rugged force transfer member which was also simple to mount in a miniature housing and which reduced the height of the switch, would be of value.
In accordance with one embodiment of the present invention, a miniature electrical switch is provided, which includes an actuator that can be pushed forwardly to operate the switch and a contacting device with a portion that can be depressed to push down an electrical conductor against a contact to close the switch. The switch includes a force transfer member in the form of a one-piece rigid molded lever that is pivotally mounted on the housing. The lever has a cam follower surface that is depressed by a ramp surface at the front end of the actuator, with the lever having a lower surface positioned to depress the contacting device.
The lever has a laterally-elongated rear branch forming trunnions at its laterally opposite sides. The trunnions fit into trunnion-receiving recesses in the housing, with the trunnions being pivotable on the housing to allow the lever to pivot. Each of the trunnions is of largely rectangular cross section, with corners joining the faces of the rectangle. A corner of the rectangle cross section, and therefore on edge of each trunnion, pivots on the housing for very simple mounting and low friction rocking pivoting.
The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.